In running a string of drill pipe or other pipe into or out of a well, a combination torque wrench and spinning wrench has been used for connecting and disconnecting the various drilling components, such as drill pipes and drill collars. Such combination torque wrenches and spinning wrenches are often referred to as xe2x80x9ciron roughnecksxe2x80x9d. These devices combine torque and spinning wrenches and are described in U.S. Pat. No. 4,023,449, U.S. Pat. No. 4,348,920, and U.S. Pat. No. 4,765,401, all to Boyadjieff, and all of which are incorporated by reference in their entirety into the present disclosure.
In the prior an iron roughnecks, spinning wrenches and a torque wrenches are mounted together on a single carriage but are, nevertheless, separate machines. When xe2x80x9cbreaking-outxe2x80x9d, or loosening, connections between two joints of drill pipe, the upper jaw of the torque wrench is used to clamp onto the end portion of an upper joint of pipe, and the lower jaw of the torque wrench clamps onto the end portion of the lower joint of pipe. Drill pipe manufacturers add threaded components, called xe2x80x9ctool jointsxe2x80x9d, to each end of a, joint of drill pipe. They add the threaded tool joints because the metal wall of drill pipe is not thick enough for threads to be cut into them. The tool joints are welded over the end portions of the drill pipe and give the pipe a characteristic bulge at each end. One tool joint, having female, or inside threads, is called a xe2x80x9cboxxe2x80x9d. The tool joint on the other end has male, or outside threads, is called the xe2x80x9cpinxe2x80x9d.
After clamping onto the tool joints, the upper and lower jaws are turned relative to each other to break the connection between the upper and lower tool joints. The upper jaw is then released while the lower jaw remains clamped onto the lower tool joint. A spinning wrench, which is separate from the torque wrench and mounted higher up on the carriage, engages the stem of the upper joint of drill pipe and spins the upper joint of drill pipe until it is disconnected from the lower joint.
Because the spinning wrench and the torque wrench are separate mechanisms, the spinning wrench cannot get close enough to the torque wrench to engage the tool joint, so the spinning wrench must engage the pipe, if at all, along its stem.
Because the spinning wrench can not get close enough to the torque wrench, the iron roughnecks of the prior art cannot be used for connecting and disconnecting some types of drill stem components. For example, spiral collars have external stabilizers along the stem which can be damaged by the rollers of a spinning wrench. Other components have other variations in surface and shape which make them unsuitable for contact with spinning rollers along their stems.
The iron roughneck of the present invention allows the automated connection and disconnection of a wide variety of drill stem components without damaging those components. The spinning wrench is integrated with the torque wrench into a single device so that the spinning rollers engage the component at the same level as the torque wrench jaws. This allows the spinning rollers to engage the tool joint rather than the pipe stem and thus avoid, for example, stabilizer blades and other features which would prevent the use of the spinning wrench of a prior iron roughneck. This integration of the spinning wrench with the torque wrench also permits the spinning and torquing of a pair of pipe joints without repositioning the torque wrench and the spinning wrench. It allows a more compact design, and provides a greater torque to drive power ratio.
Other features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.